The wreck of the HMS Erebus, above, was found in 2014 west of O'Reilly Island in Nunavut. (Parks Canada)

In 1819 the geography of North America was little better known than that of Baffin Bay. It was widely accepted, even by Barrow [Second Secretary of the British Admiralty], that Canada had to stop somewhere. But its northern coastline had only been touched upon in two places. In 1789 Alexander Mackenzie had followed the river since named after him and found open sea at a point about 1,000 miles east of Bering Strait. He had been preceded in 1771 by Samuel Hearne who had done the same with the Coppermine River, meeting the ocean 500 miles east of the Mackenzie. Franklin's job was to fill in the gaps.

Barrow's intention was that Franklin should travel overland with boats and canoes to the Great Slave Lake, follow the Coppermine River from there to its mouth and then take to the sea. He would take a bare minimum of naval personnel, using hired help supplied by the Hudson's Bay Company or its larger competitor, the North West Company. Orkney boatmen would see him through the first part of his journey, after which their place would be taken by Canadian porters, or voyageurs, who would escort him from the Great Slave Lake to the coast. Indian and Eskimo guides would assist him and provide whatever food was necessary should his stores run out.

On reaching the coast he was advised to go east, either to rendezvous with Parry or to make his way to Repulse Bay, but if he wanted he could go west to the Mackenzie and if he really felt like it he could even go north into the unknown.....
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'It is impossible to describe our sensations', Richardson wrote, 'when, on attaining the eminence that overlooks [Fort Enterprise] we beheld the smoke issuing from one of the chimneys.' During their journey he and Hepburn had lived off nothing but tripes de roche [rock-scraped lichens] and Hood's hide blanket. Richardson was now so weak that he fell down twenty times covering a distance of only 100 yards. However, the prospect of salvation gave them strength and on the evening of 29 October they flung open the door of Fort Enterprise.

'No words can convey an idea of the filth and wretchedness that met our eyes', Richardson wrote. The floor had been pulled up [for firewood], the partitions had been demolished and the skin off the windows was gone [eaten]. Of the four men present -- Franklin, Samandre, Adam and Peltier -- only Peltier seemed able to move. He had risen, expecting them to be an Indian relief party. Now he sank back in despair. Accustomed as Hepburn and Richardson were to the sight of each others' emaciated frames, 'the ghastly countenances, dilated eye-balls, and sepulchral voices of Captain Franklin and those with him were more than we could at first bear'.

Richardson and Hepburn had been expecting Franklin to help them. Now they found themselves having to help him. Despite their weakness they were both far stronger than any man in the building and from that day they undertook the chores of chopping wood and carrying it home. They also went hunting, but were too enfeebled to hold the gun steady on the rare occasions when they encountered game. Franklin, meanwhile, dragged in deer skins from the pile which had been discarded the previous winter. The pile was thirty yards away. Franklin managed to bring back three skins in a day. There were about twenty-six skins in all, thin, rotten things, riddled with warble-fly grubs. The explorers devoured them avidly, right down to the warble grubs which they squeezed out of the hide with their fingernails. They tasted 'as fine as gooseberries'.

Contrarily, while Peltier had previously been one of the healthiest in the group, he now collapsed, and Adam showed signs of renewed life. Richardson [expedition doctor] diagnosed Adam's swollen limbs as the result of protein-deficiency oedema and incised his abdomen, scrotum and legs, whereby 'a large quantity of water flowing out he obtained some ease'. But there was nothing else he could do for Peltier or Samandre. They both died on the night of 1 November.

Richardson and Hepburn now began to flag. On 3 November Richardson noted that Hepburn's limbs were beginning to swell -- 'his strength as well as mine is declining rapidly'. That day they ate the last of the bones.

On 5 November Adam began to wander, leaping to his feet and seizing his gun with the promise of a good day's hunting and food for all, before subsiding into a dejection so deep that he could not even be persuaded to eat. The others were little better off. They tried not to talk about their situation, chatting instead about 'common and light subjects'. But as Franklin wrote, 'our minds exhibited symptoms of weakness, evinced by a kind of unreasonable pettishness with each other. Each of us thought the other weaker in intellect than himself, and more in need of advice and assistance. So trifling a circumstance as a change of place, recommended by one as being more warm and comfortable, and refused by the other, from a dread of motion, frequently called forth fretful expressions, which were no sooner uttered than atoned for, to be repeated, perhaps in the course of a few minutes.'

They were all so thin that it hurt even to sleep. Their bones ached against the floorboards but they put up with it because the pain of turning to a more comfortable position was even greater. To this was added initially the pain of constant hunger. But once the pangs had eased -- after three or four days -- they usually enjoyed a few hours in which they dreamed of limitless food.

On 7 November Richardson and Hepburn were in the storehouse, trying to separate logs from the frozen pile stored there the previous winter, when they heard a shot. Three of Akaitcho's Indians were outside They had been contacted by Back two days previously and on hearing his tale, and on taking in his shrivelled appearance -- he too was pathetically reduced, and had lost one man from his party -- they had immediately set out with emergency rations comprising fat, some dried venison and a few deer tongues.

Sending the youngest of them back for further supplies, the remaining two Indians swiftly took control. They cleared Fort Enterprise of its corpses, swept out the wet, blackened filth of charred bones and singed hair that covered the floor, and built up a crackling fire. The ease with which they did all this stunned Richardson. 'We could scarcely', he wrote, 'by any effort of reasoning, efface from our minds the idea that they possessed a supernatural degree of strength'.

Then came the feeding. Despite Richardson's injunction to 'be moderate!', they all suffered severely from overeating. Richardson, who should have known better, devoured the food as extravagantly as the others. For days afterwards -- weeks, in Richardson's case -- they suffered from distention and indigestion. The passing of a stool caused immense pain Only Adam, who had to be spoon-fed, escaped the effects of sudden indulgence.

The Indians treated the survivors 'with the same tenderness they would have bestowed on their own infants'. They persuaded them to wash and to shave their beards which had not been touched since they left the coast and which had grown to a 'hideous length'. On learning that the Europeans had eaten too much meat they strung lines across the river and came back with four large trout. In every respect they could not have been more solicitous.

But hardly had salvation arrived than it departed. On 13 November the Indians vanished, leaving behind them a handful of pemmican per man. For a while Franklin feared his men would have to revert to their old diet, save that instead of deer skins they now had fish skins. It transpired, however, that the Indians, fearing their messenger had not reached base, had left on a twenty-four-hour march to fetch more supplies from Akaitcho's camp. The Indians reappeared on the morning of 15 November, having walked through a stormy and snow-filled night with two of their wives and Benoit, one of the voyageurs who had accompanied Back, Once again the survivors were faced with an abundance of food, but this time they measured their pace. On 16 November, a sunny Thursday, they left Fort Enterprise for good.

From Barrow's Boys ... A stirring story of daring fortitude, and outright lunacy, by Fergus Fleming

Shown is the route of Sir John Franklin's final expedition from 1845-47.